Integrator compensator for improving accuracy

ABSTRACT

1. In a mechanical integrator having a base, a pair of spaced parallel supporting brackets secured to said base and extending outwardly therefrom, a disk rotatably mounted on said base between said brackets, a roller rotatably mounted between said brackets with the axis thereof disposed perpendicular to and intersecting the axis of said disk, lead screw means rotatably supported by and between said brackets with the axis thereof disposed parallel to the axis of said roller, a carriage mounted on said lead screw means for back and forth movement radially of said disk, and a pair of contacting balls carried by said carriage with one of said balls engaging said disk and the other of said balls engaging said roller, that improvement which comprises; a ball cage in which said balls are mounted, said cage being slidably mounted in said carriage for back and forth movement parallel to the axes of said roller and said lead screw means, a bar secured in fixed position parallel to the axes of said roller and said lead screw means, a flexible track disposed substantially parallel to said bar, a plurality of longitudinally spaced adjusting means by which said track is secured to said bar and by which individual sections of said track may be adjusted back and forth with respect to said bar, a lever pivotally secured intermediate the ends thereof to said carriage with one end thereof disposed in engagement with said ball cage and the other end thereof disposed in engagement with said track, and spring means yieldingly holding said ball cage in engagement with the contacting end of said lever.

United States Patent 1 Weaver 541 INTEGRATOR COMPENSATOR FOR IMPROVING ACCURACY [75] Inventor: William I. Weaver, New Hyde Park,

[73] Assignee: Sperry Rand Corporation, Ford Instrument Company Division, Long Island City, NY.

[22] Filed: March 26, 1957 [2l] Appl.No.: 649,590

[52] US. Cl. ..235/61 C [51 Int. Cl. ..G06g 3/08 [58] Field of Search ..235/6l C, 61 GM [56] References Cited UNITED STATES PATENTS 2,923,468 2/1960 Rappaport ..235/61 C Primary ExaminerSamuel Feinberg Assistant Examiner-H. A. Birmiel Attorney-Borst and Borst EXEMPLARY CLAIM 1. In a mechanical integrator having a base, a pair of spaced parallel supporting brackets secured to said base and extending outwardly therefrom, a disk 1 March 6, 1973 rotatably mounted on said base between said brackets, a roller rotatably mounted between said brackets with the axis thereof disposed perpendicular to and intersecting the axis of said disk, lead screw means rotatably supported by and between said brackets with the axis thereof disposed parallel to the axis of said roller, a carriage mounted on said lead screw means for back and forth movement radially of said disk, and a pair of contacting balls carried by said carriage with one of said balls engaging said disk and the other of said balls engaging said roller, that improvement which comprises; a ball cage in which said balls are mounted, said cage being slidably mounted in said carriage for back and forth movement parallel to the axes of said roller and said lead screw means, a bar secured in fixed position parallel to the axes of said roller and said lead screw means, a flexible track disposed substantially parallel to said bar, a plurality of longitudinally spaced adjusting means by which said track is secured to said bar and by which individual sections of said track may be adjusted back and forth with respect to said bar, a lever pivotally secured intermediate the ends-thereof to said carriage with one end thereof disposed in engagement with said ball cage and the other end thereof disposed in engagement with said track, and spring means yieldingly holding said ball cage in engagement with the contacting end of said lever.

20 Claims, 5 Drawing Figures PATENTEW 51375 SHEET 10F 3 INVENTOR. M4 L/AM R W54 vae INTEGRATOR COMPENSATOR FOR IMPROVING ACCURACY This invention relates generally to calculating mechanisms which are extensively used for automatically computing various types of data including gun fire control data and both air and sea navigation data. More specifically, the invention relates to a mechanical integrator which is a component part of such calculating mechanisms.

The integrator with which this invention is concerned is generally known as a DBR integrator or disk, ball and roller integrator. Such integrators comprise a rotatable disk, a roller which is spaced from the disk with the axis thereof disposed perpendicular to and intersecting the axis of the disk, and a pair of contacting balls which are interposed between the disk and the roller with one of the balls contacting the disk and the other of the balls contacting the roller. The balls are mounted in a carriage which in turn is mounted upon a pair of lead screws the axes of which are parallel to the axis of the roller. The lead screws are operative to move the carriage and with it the balls back and forth across the disk. The rotation of the disk will impart rotation to the ball which in turn impart rotation to the roller. A fixed R.P.M. of the disk will impart through the balls a proportional RPM to the roller, the closer the balls are to the axis of the disk the lesser the RPM imparted to the roller and vice versa; and the farther the balls are from the axis of rotation of the disk the greater the RPM imparted to the roller. In operation one value is imparted to the disk and another value is imparted to the lead screws and the output of the roller is the resultant or integral of the two values imparted to the integrator. Knowing the RPM of the disk and the diameter of the roller the output in RPMs of the roller can be accurately figured for any and every position of the balls between the axis of the disk and the periphery thereof. The accuracy of the integrator can then be checked by comparing the actual output of the roller with the calculated output.

It has been found in practice that the actual output of the rollerdoes not always agree with the calculated output thereof and that this is due to two factors, one of which is that due to manufacturing tolerances the diameter of the roller may vary between end to end thereof and the the other of which is the variation in atmospheric temperature between uses of the integrator. Obviously if the diameter of the roller at a given point is less than the calculated diameter the output of the roller in RPMs will be greater than the calculated output and if it is greater than the calculated diameter the output in RPMs will be less than the calculated output. Also it is obvious the variations in atmospheric temperature will vary the diameter of the roller and the length of the lead screws and that variations in the length of the lead screws will vary the contacting position of the balls and the disk with respect to the axis of the disk.

It is therefor the principal object of this invention to provide means in a mechanical integrator of the aforesaid type by which manufacturing tolerances in the construction thereof may be compensated therefor.

And it is a further object of this invention to so construct and arrange the aforesaid compensating means in such a manner that it will also automatically compensate for variations in ambient temperatures during which the integrator is used.

The principal objects of the invention having been stated other and more limited objects of the invention will be apparent from the following specification and the accompanying drawings forming a part thereof in which:

FIG. 1 is a plan view, with sections partially broken away, of a mechanical integrator of the aforesaid type, having my invention incorporated therein;

FIG. 2 is a horizontal sectional view taken substantially on the line 2-2 of FIG. 3;

FIG. 3 is a longitudinal section taken on the line 3-3 of FIG. 1;

FIG. 4 is a transverse sectional view taken substantially on the line 4-4 of FIG. 1; and

FIG. 5 is a detail diagramatic view of the compensating lever.

Referring now to the drawings by reference characters the numeral 1 indicates generally a conventional well known mechanical integrator having my invention incorporated therein. The integrator 1 comprises a horizontal base 2 having a pair of spaced parallel upwardly extending similar supports 3 and 4 suitably secured thereto as by bolts or screws 5. The base 2 is provided with a central upwardly extending post 6 and an annular recess 7 in the upper surface thereof. A gear 8 is rotatably mounted upon the post 6 by means of an anti-friction bearing 9 and is supported adjacent the periphery thereof by a thrust bearing 10 which is disposed in an annular recess 7 in the upper surface thereof. The base 2 and gear 8 are provided with cutouts 11 for the sake of lightness. A disk 12 is suitably secured to the upper face of the gear 8 for rotation therewith. A cylindrical roller 14 is disposed between the supports 3 and 4 above and in spaced relation to the disk 12 with the axis of the roller 14 perpendicular to and intersecting the axis X-X of the disk 12 and gear 8. The roller 14 is rotatably supported by anti-friction bearings 15 carried by a rectangular plate 16 which is pivotally mounted between the upper ends of the supports 3 and 4 upon a pair of opposed axially aligned pivot studs 17 which are carried by the supports 3 and 4 A pair of similar vertically aligned contacting balls 20 and 21 having the centers thereof disposed in a vertical plane which includes the axes of the roller 14 and disk 12 are mounted in a carriage 22 with the ball 20 in contact with the roller 14 and the ball 21 in contact with the disk 12. The carriage 22 is mounted upon a pair of spaced parallel lead screws 23 and 24 which are rotatably supported by and between the supports 3 and 4 with the axes thereof parallel to the axis of the roller 14. The lead screws 23 and 24 are each provided at one ed thereof with a spur gear 25 through which the lead screws 23 and 24 are rotated in unison by a gear 26 which meshes with both of the gears 25. The gear 26 is secured to a shaft 27 which is mounted in a bracket 28 secured to the support 3. The shaft 27 has a gear 29 secured to the outer end thereof through which the shaft 27 and gear 26 are rotated. Rotation of the lead screws 23 and 24 will move the carriage 22 and with it the balls 20 and 21 back and forth across the disk 12. The balls 20 and 21 are maintained in firm contact with each other and with the disk 12 and roller 14 by a pair of compression springs 30 which are interposed between fixed studs 31 carried by the plate 16 adjacent the rear end thereof and aligned adjustable studs 32 carried by the base 2. The springs 30 tend to rock the plate about its supporting studs 17 and yielding hold the roller 14in firm contact with the ball 20. The pressure exerted by the springs 30 may be regulated by adjusting the studs 32 up or down in the base 2.

In use the gear 8 and disk 12 are rotated by a gear 35 which meshes with the gear 8 and is suitably connected to one input source; and the lead screws 23 and 24 are rotated in unison from another input source by a gear 36 which meshes with the gear 29 which in turn through the shaft 27 and gears 26 and 25 impart rotation to the lead screws 23 and 24. Rotation of the disk 12 imparts rotation to the roller 14 through the balls and 21; and the output of the roller 14 is delivered to a receiving source through the roller shaft 37 and a gear 38 secured to the end thereof. The RPMs imparted to the roller 14 for a given RPM of the disk 12 are dependent upon the distance of the line of contact YY between the disk, balls and roller froin the axis XX of the disk 12 and the diameter of the roller at the line YY. The further the line of contact YY is from the axis XX of the disk 12 the greater the number of RPMs imparted to the roller 14 per RPM of the disk 12; and the smaller the diameter of the roller 14 at the line of contact YY the greater the number of RPMs imparted to the roller 14 per RPM of the disk 12. The integrator thus far described is of standard well known construction.

My improved adjusting and compensating mechanism is applied to an integrator of the aforesaid type will now be described. In accordance with one form of my invention I form the base 2 of material having a greater coefficient of expansion than that of which the lead screws 23 and 24 are formed, preferably aluminum and steel, respectively. As previously stated when the distance the line YY is from the axis XX of the disk 12 and the diameter of the roller 14 at the line YY are known the number of RPMs imparted to.

the roller 14 per RPM of the disk 12 can be accurately figured after which the accuracy of the integrator can be determined by checking the actual output in RPMs of the roller 14. Theoretically the diameter of the roller 14 is supposed to be uniform throughout its length, but it has been found in practice that due to manufacturing tolerances the diameter of the roller 14 may vary slightly throughout its length which will cause an error in the output of the roller 14. It has also been found in practice that the ambient temperature affects the relation between the line of contact YY and the axis X- X of the disk 12 in that an increase in temperature will increase the distance between the axis XX and the line of contact YY and in the diameter of the roller 14, which will also cause an error in the output of the roller 14. In accordance with my invention I incorporate a single adjusting and compensating means in an integrator of the aforesaid character by which both the errors due to the variation in the diameter of the roller due to manufacturing tolerances and the errors due to variation in the ambient temperature are automatically compensated for.

This adjusting and compensating means comprises a cage 41, an adjustable track 42 and a pivoted lever 43.

The cage 41 which is provided with a vertical cylindrical bore 44 in which the balls 20 and 21 are mounted is slidably mounted in a chamber 45 in the carriage 22 for slight back and forth movement in a plane which includes the axis of the roller 14, the axis of the disk 12, and the centers of the balls 20 and 21. A compression spring 46 yieldingly biases the cage 41 toward the axis XX of the disk 12. The cage 41 is removably secured in the chamber 45 by a cap 47 which is provided with an elongated aperture 48 through which the ball 20 projects; and the carriage 22 is provided with an elongated aperture 49 below the chamber 45 through which the ball 21 projects.

The track 42 which consists of an elongated flexible sheet metal strip is secured by a plurality of spaced adjusting screws 50 to a bar 51 which is secured to and extends between the rear ends of the supports 3 and 4 parallel to the axes of the lead screws 23 and 24. A similar bar 52 is secured to and between the forward ends of the supports 3 and 4. The adjusting screws 50 which are rotatably mounted in complementary threaded apertures 53 in the bar 51 are provided with spaced collars 54 between which the track 42 is mounted. By rotating the screws 50 selected sections of the track 42 can be adjusted toward and away from the bar 51.

The lever 43 is formed from suitable thin stiff metal and comprises an elongated body section 55 which is bent downwardly and then forwardly as shown at 56 and terminates in an outwardly extending arm 57. The body section 55 is also provided with an arm 58 which is spaced from the arm 57 and extends outwardly from the section 55 in the same direction as and parallel to the arm 57, and is pivotally secured to the top of the carriage 22 as indicated at 59. The arm 57 extends through a slot 60 in the carriage 22 into engagement with the cage 41; and the other end of the lever 43 is provided with a roller 61 which engages the track 42. The pivot point 59 of the lever 43 is preferably disposed in the plane YY which passes through the centers of the balls 20 and 21 perpendicular to the axes of the lead screws 23 and 24. The spring 46 yieldingly maintains the cage 41 in contact with the end of the arm 57 and the roller 61 in contact with the track 42.

By reference to FIG. 5 it will be seen that the lever 43 is so constructed, proportioned and mounted that a vertical plane passing through the point of contact A of the lever 43 with the track 44 and the point of contact B" thereof with the cage 41 will form with a vertical plane passing through the pivot point 59 and the contact point A and a vertical plane passing through the pivot point 59 and the contact point B a triangle in which the leg A-B" is longer than either of the other two legs. It will also be seen that the leg AB" intersects the track 42 at an acute angle C and that the leg A59 intersects the track 42 at an acute angle D" which is less than the anglefC."

The manner of adjusting the mechanism to compensate for varying diameters of the roller 14 throughout its length due to manufacturing tolerances will now be described, it being born in mind that the RPM output of the roller 14 will be greater per RPM of the disk 12 if the diameter of the roller is undersize; and that the greater the distance between the centers of the balls 20 and 21 and the axis of the disk 12 the greater the RPM output of the roller 14 per RPM of the disk 12. By reference to FIGS. 1 and 5, it will be apparent that the farther the track 42 is from the bar 52 the farther the centers of the balls and 21 will be from the center of the disk 12 for any given position of the carriage 22. Therefor in checking the accuracy of the integrator, the theoretical output of the roller 14 is figured for various positions of the carriage 22 and the balls 20 and 21 from the center of the disk 12, and then the actual output of the roller 14 is checked. If the actual output is greater than the figured output for that position of the balls, it indicates that the roller 14 at that point is under size. The track 42 at the point of contact A" thereof with the lever 43 is therefor adjusted back towards the bar 51 by the appropriate screw 50 which permits the spring 46 to move the cage 41 and balls 20 and 21 back toward the center of the disk 12 thereby decreasing the RPM output of the roller 14 per RPM of the disk 12. The track is then left in the position where the actual output of the roller 14 and the figured output thereof are equal. If, however, the actual output of the roller 14 is less than the figured output thereof it indicates that the diameter of the roller at that point is oversize. The track 42 is therefor adjusted further out from the bar 51 which causes the lever 43 to move the cage 41 and balls 20 and 21 further away from the center of the disk 12 thereby increasing the RPM output of the roller 14 per RPM of the disk 12. This procedure is then followed for various different positions of the carriage 22 between the ends of the roller 14.

In order that the lever 43 and the slidably mounted ball carriage 22 may also be utilized to automatically compensate for variations in the ambient temperature I mount the gear ends of the lead screws 23 and 24 in bearings 65, which are secured in fixed position in the support 3, in such a manner that the lead screws 23 and 24 will move with the support 3 as it shifts back and forth with the base 2 upon expansion and contraction thereof due to changes in ambient temperature; and l slidably mount the other ends of the lead screws 23 and 24 in bearing 66 carried by the support 4 whereby the support 4 may shift back and forth independently of the lead screws 23 and 24.

The manner in which this automatic compensation for variations in temperature is accomplished will now be described, it being born in mind that the diameter of the roller varies in accordance with variations in temperature and that the length of the lead screws 23 and 24 also varies with changes in temperature. An increase in temperature will increase the diameter of the roller 14 and length of the lead screws 23 and 24, and a decrease in temperature will decrease the diameter of the roller 14 and the length of the lead screws 23 and 24. Normally an increase in the length of the lead screws 23 and 24 will cause an increase in the output of the roller 14 when the carriage 22 and balls 20 and 21 are between the axis of rotation XX of the disk 12 and the support 4, and will cause a decrease in the output of the roller 14 when the carriage 22 and balls 20 and 21 are between the axis of the disk 12 and the support 3; and as previously stated an increase in the diameter of the roller 14 will cause a decrease in the output thereof regardless of the position of the carriage and balls with respect to the axis of the disk 12; and a decrease in the diameter of the roller 14 will cause an increase in the output thereof.

In this connection let us first consider an increase in ambient temperature with the carriage 22 and balls 20 and 21 between the disk axis XX and the support 3.

An increase in temperature will increase the diameter of the roller 14 which will decrease the output of the roller 14, and will elongate the lever 43 thereby moving the balls 20 and 21 toward the axis of the disk 12 which will tend to further decrease the output of the roller 14. An increase in temperature will also elongate the lead screws 23 and 24 which will move the carriage 22 and balls 20 and 21 toward the axis of the disk and apparently still further decrease the output of the roller 14. But due to the fact that the expansion of the aluminum base 2, between the axis XX and the support 3 to which the gear ends of the lead screws 23 and 24 are anchored, is much greater than the elongation of the steel lead screws 23 and 24 between the support 3 and the axis XX, an increase in temperature actually effects the movement of the carriage 22 and balls 20 and 21 away from the center of the disk 12 and not toward the disk center which thereby increases the output of the roller 14. This increase in output is compensated for by the increase in the diameter of the roller 14 and the movement of the balls 20 and 21 in the carriage 22 toward the center of the disk 12 by the elongation of the lever 43. The reverse is true for a decrease in temperature.

Let us now consider an increase in ambient temperature with the carriage 22 and balls 20 and 21 between the axis of rotation XX of the disk 12 and the support 4 as shown in the drawings. An increase in temperature will increase the diameter of the roller 14 and thereby decrease the output thereof, and will elongate the lever 43 thereby moving the balls 22 and 23 farther away from the axis of rotation of the disk 12 which will increase the output of the roller 14. An increase in temperature will also elongate the lead screws 23 and 24 tending to move the carriage 22 and with it the balls 20 and 21 farther away from the disk axis which apparently still further increases the output of the roller 14. But due to the fact that the expansion of the aluminum base 2 between the axis XX and the support 3 to which the lead screws 23 and 24 are anchored is greater than the elongation of the steel lead screws 23 and 24 between the plane Y-Y and the support 3, an increase in temperature actually effects the movement of the carriage 22 and balls 20 and 21 toward the center of the disk 12 and not away from the disk center which thereby decreases the output of the roller 14. The combined decrease in roller output caused by the increase in the diameter of the roller and the shifting of the carriage toward the center of the disk is compensated for by the elongation of the lever 43 by which the balls 20 and 21 are moved in the carriage 22 away from the center of the disk, it being understood that the distance the balls 20 and 21 are moved away from the center of the disk 12 is greater than the distance the carriage 22 is moved toward the center of the disk. The reverse in true for a decrease in temperature.

From the foregoing it will be apparent to those skilled in this art that l have provided very simple and efficient means for accomplishing the objects of the invention.

And it is to be understood that I am not limited to the specific construction shown and described herein as various modifications may be made therein within the spirit of the invention and the scope of the appended claims.

lclaim:

1. In a mechanical integrator having a base, a pair of spaced parallel supporting brackets secured to said base and extending outwardly therefrom, a disk rotatably mounted on said base between said brackets, a roller rotatably mounted between said brackets with the axis thereof disposed perpendicular to and intersecting the axis of said-disk, lead screw means rotatably supported by and between said brackets with the axis thereof disposed parallel to the axis of said roller, a carriage mounted on said lead screw means for back and forth movement radially of said disk, and a pair of contacting balls carried by said carriage with one of said balls engaging said disk and the other of said balls engaging said roller, that improvement which comprises; a ball cage in which said balls are mounted, said cage being slidably mounted in said carriage for back and forth movement parallel to the axes of said roller and said lead screw means, a bar secured in fixed position parallel to the axes of said roller and said lead screw means, a flexible track disposed substantially parallel to said bar, a plurality of longitudinally spaced adjusting means by which said track is secured to said bar and by which individual sections of said track may be adjusted back and forth with respect to said bar, a lever pivotally secured intermediate the ends thereof to said carriage with one end thereof disposed in engagement with said ball cage and the other end thereof disposed in engagement with said track, and spring means yieldingly holding said ball cage in engagement with the contacting end of said lever.

2. The improvement in mechanical integrators as defined in claim 1 in which one end of said lead screw means is rotatably mounted in one of said brackets and is constrained against longitudinal movement with respect thereto and the other end of said lead screw means is rotatably and slidably mounted in the other of said brackets.

3. The improvement in mechanical integrators as defined in claim 2 in which said lever comprises a body section, one end of which engages said track, and two spaced outwardly extending arms one of which is pivotally secured to said carriage and the other of which engages said cage.

4. The improvement in mechanical integrators as defined in claim 2 in which said lever is so constructed and mounted that a vertical plane passing through the pivot point of said lever and the point of contact of said lever with said track intersects the plane of said track at an oblique angle.

5. The improvement in mechanical integrators as defined in claim 2 in which said lever is so constructed and mounted that the pivot point of said lever is laterally offset from a vertical plane passing through point of said lever and the point of contact thereof with said cage, an acute-angled triangle in which the leg of said triangle extending between the points of contact of said lever with said cage and said track is greater than either of the other two legs of said triangle.

7. The improvement in mechanical integrators as defined in claim 1 in which said lever comprises a body section, one end of which engages said track, and two spaced outwardly extending arms one of which is pivotally secured to said carriage and the other of which engages said cage.

8. The improvement in mechanical integrators as defined in claim 1 in which said lever is so constructed and mounted that a vertical plane passing through the pivot point of said lever and the point of contact of said lever with said track intersects the plane of said track at an oblique angle.

9. The improvement in mechanical integrators as defined in claim 1 in which said lever is so constructed and mounted that the pivot point of said lever is laterally offset from a vertical plane passing through the points of contact of said lever with said track and said cage.

10. The improvement in mechanical integrators as defined in claim 1 in which said lever is so constructed and arranged that a vertical plane passing through the points of contact of said lever with said track and said cage forms, with a plane passing through the pivot point of said lever and the point of contact thereof with said track and a vertical plane passing through the pivot point of said lever and the point of contact thereof with said cage, an acute-angled triangle in which the leg of said triangle extending between the points of contact of said lever with said cage and said track is greater than either of the other two legs of said triangle.

11. The improvement in mechanical integrators as defined in claim 1 in which said lead screw means comprises a pair of spaced parallel lead screws and in which one end of each of said lead screws is rotatably mounted in one of said brackets and is constrained against longitudinal movement with respect thereto and the opposite end of each of said lead screws is rotatably and slidably mounted in the other of said brackets.

12. The improvement in mechanical integrators as defined in claim 11 in which said lever comprises a body section, one end of which engages said track, and two spaced outwardly extending arms one of which is pivotally secured to said carriage and the other of which engages said cage.

13. The improvement in mechanical integrators as defined in claim 1 1 in which said lever is so constructed and mounted, that a vertical plane passing through the pivot point of said lever and the point of contact of said lever with said track intersects the plane of said track at an oblique angle.

14. The improvement in mechanical integrators as defined in claim 1 l in which said lever is so constructed and mounted that the pivot point of said lever is laterally offset from a vertical plane passing through the points of contact of said lever with said track and said cage.

15. The improvement in mechanical integrators as defined in claim 1 l in which said lever is so constructed and arranged that a vertical plane passing through the points of contact of said lever with said track and said cage forms, with a plane passing through the pivot point of said lever and the point of contact thereof with said track and a vertical plane passing through the pivot point of said lever and the point of contact thereof with said cage, an acute-angled triangle in which the leg of said triangle extending between the points of contact of said lever with said cage and said track is greater than either of the other two legs of said triangle.

16. The improvement in mechanical integrators as defined in claim 1 in which the pivot point of said lever is offset from a vertical plane passing through the points of contact of said lever with said cage and said track and is disposed in a vertical plane passing through the centers of said balls perpendicular to the axis of said roller.

17. The improvement in mechanical integrators as defined in claim 1 in which the base of said integrator is formed from material having a greater coefficient of expansion than the coefficient of expansion of the material from which the lead screw means of said integrator is formed.

18. The improvement in mechanical integrators as defined in claim 17 in which one end of said lead screw means is rotatably mounted in one of said brackets and is constrained against longitudinal movement with respect thereto, and the other end of said lead screw means is rotatably and slidably mounted in the other of said brackets.

19. The improvement in mechanical integrators as defined in claim 18 in which the pivot point of said lever is offset from a vertical plane passing through the points of contact of said lever with said cage and said track and is disposed in a vertical plane passing through the centers of said balls perpendicular to the axis of said roller.

20. The improvement in mechanical integrators as defined in claim 19 in which said lever is so constructed and arranged that a vertical plane passing through the points of contact of said lever with said track and said cage forms with a plane passing through the pivot point of said lever and the point of contact thereof with said track and a vertical plane passing through the pivot point of said lever and the point of contact thereof with said cage, a triangle in which the leg of said triangle extending between the points of contact of said lever with said cage and said track is greater than either of the other two legs of said triangle. 

1. In a mechanical integrator having a base, a pair of spaced parallel supporting brackets secured to said base and extending outwardly therefrom, a disk rotatably mounted on said base between said brackets, a roller rotatably mounted between said brackets with the axis thereof disposed perpendicular to and intersecting the axis of said disk, lead screw means rotatably supported by and between said brackets with the axis thereof disposed parallel to the axis of said roller, a carriage mounted on said lead screw means for back and forth movement radially of said disk, and a pair of contacting balls carried by said carriage with one of said balls engaging said disk and the other of said balls engaging said roller, that improvement which comprises; a ball cage in which said balls are mounted, said cage being slidably mounted in said carriage for back and forth movement parallel to the axes of said roller and said lead screw means, a bar secured in fixed position parallel to the axes of said roller and said lead screw means, a flexible track disposed substantIally parallel to said bar, a plurality of longitudinally spaced adjusting means by which said track is secured to said bar and by which individual sections of said track may be adjusted back and forth with respect to said bar, a lever pivotally secured intermediate the ends thereof to said carriage with one end thereof disposed in engagement with said ball cage and the other end thereof disposed in engagement with said track, and spring means yieldingly holding said ball cage in engagement with the contacting end of said lever.
 1. In a mechanical integrator having a base, a pair of spaced parallel supporting brackets secured to said base and extending outwardly therefrom, a disk rotatably mounted on said base between said brackets, a roller rotatably mounted between said brackets with the axis thereof disposed perpendicular to and intersecting the axis of said disk, lead screw means rotatably supported by and between said brackets with the axis thereof disposed parallel to the axis of said roller, a carriage mounted on said lead screw means for back and forth movement radially of said disk, and a pair of contacting balls carried by said carriage with one of said balls engaging said disk and the other of said balls engaging said roller, that improvement which comprises; a ball cage in which said balls are mounted, said cage being slidably mounted in said carriage for back and forth movement parallel to the axes of said roller and said lead screw means, a bar secured in fixed position parallel to the axes of said roller and said lead screw means, a flexible track disposed substantIally parallel to said bar, a plurality of longitudinally spaced adjusting means by which said track is secured to said bar and by which individual sections of said track may be adjusted back and forth with respect to said bar, a lever pivotally secured intermediate the ends thereof to said carriage with one end thereof disposed in engagement with said ball cage and the other end thereof disposed in engagement with said track, and spring means yieldingly holding said ball cage in engagement with the contacting end of said lever.
 2. The improvement in mechanical integrators as defined in claim 1 in which one end of said lead screw means is rotatably mounted in one of said brackets and is constrained against longitudinal movement with respect thereto and the other end of said lead screw means is rotatably and slidably mounted in the other of said brackets.
 3. The improvement in mechanical integrators as defined in claim 2 in which said lever comprises a body section, one end of which engages said track, and two spaced outwardly extending arms one of which is pivotally secured to said carriage and the other of which engages said cage.
 4. The improvement in mechanical integrators as defined in claim 2 in which said lever is so constructed and mounted that a vertical plane passing through the pivot point of said lever and the point of contact of said lever with said track intersects the plane of said track at an oblique angle.
 5. The improvement in mechanical integrators as defined in claim 2 in which said lever is so constructed and mounted that the pivot point of said lever is laterally offset from a vertical plane passing through the points of contact of said lever with said track and said cage.
 6. The improvement in mechanical integrators as defined in claim 2 in which said lever is so constructed and arranged that a vertical plane passing through the points of contact of said lever with said track and said cage forms, with a plane passing through the pivot point of said lever and the point of contact thereof with said track and a vertical plane passing through the pivot point of said lever and the point of contact thereof with said cage, an acute-angled triangle in which the leg of said triangle extending between the points of contact of said lever with said cage and said track is greater than either of the other two legs of said triangle.
 7. The improvement in mechanical integrators as defined in claim 1 in which said lever comprises a body section, one end of which engages said track, and two spaced outwardly extending arms one of which is pivotally secured to said carriage and the other of which engages said cage.
 8. The improvement in mechanical integrators as defined in claim 1 in which said lever is so constructed and mounted that a vertical plane passing through the pivot point of said lever and the point of contact of said lever with said track intersects the plane of said track at an oblique angle.
 9. The improvement in mechanical integrators as defined in claim 1 in which said lever is so constructed and mounted that the pivot point of said lever is laterally offset from a vertical plane passing through the points of contact of said lever with said track and said cage.
 10. The improvement in mechanical integrators as defined in claim 1 in which said lever is so constructed and arranged that a vertical plane passing through the points of contact of said lever with said track and said cage forms, with a plane passing through the pivot point of said lever and the point of contact thereof with said track and a vertical plane passing through the pivot point of said lever and the point of contact thereof with said cage, an acute-angled triangle in which the leg of said triangle extending between the points of contact of said lever with said cage and said track is greater than either of the other two legs of said triangle.
 11. The improvement in mechanical integrators as defined in claim 1 in which said lead screw means comprises a pair of spAced parallel lead screws and in which one end of each of said lead screws is rotatably mounted in one of said brackets and is constrained against longitudinal movement with respect thereto and the opposite end of each of said lead screws is rotatably and slidably mounted in the other of said brackets.
 12. The improvement in mechanical integrators as defined in claim 11 in which said lever comprises a body section, one end of which engages said track, and two spaced outwardly extending arms one of which is pivotally secured to said carriage and the other of which engages said cage.
 13. The improvement in mechanical integrators as defined in claim 11 in which said lever is so constructed and mounted that a vertical plane passing through the pivot point of said lever and the point of contact of said lever with said track intersects the plane of said track at an oblique angle.
 14. The improvement in mechanical integrators as defined in claim 11 in which said lever is so constructed and mounted that the pivot point of said lever is laterally offset from a vertical plane passing through the points of contact of said lever with said track and said cage.
 15. The improvement in mechanical integrators as defined in claim 11 in which said lever is so constructed and arranged that a vertical plane passing through the points of contact of said lever with said track and said cage forms, with a plane passing through the pivot point of said lever and the point of contact thereof with said track and a vertical plane passing through the pivot point of said lever and the point of contact thereof with said cage, an acute-angled triangle in which the leg of said triangle extending between the points of contact of said lever with said cage and said track is greater than either of the other two legs of said triangle.
 16. The improvement in mechanical integrators as defined in claim 1 in which the pivot point of said lever is offset from a vertical plane passing through the points of contact of said lever with said cage and said track and is disposed in a vertical plane passing through the centers of said balls perpendicular to the axis of said roller.
 17. The improvement in mechanical integrators as defined in claim 1 in which the base of said integrator is formed from material having a greater coefficient of expansion than the coefficient of expansion of the material from which the lead screw means of said integrator is formed.
 18. The improvement in mechanical integrators as defined in claim 17 in which one end of said lead screw means is rotatably mounted in one of said brackets and is constrained against longitudinal movement with respect thereto, and the other end of said lead screw means is rotatably and slidably mounted in the other of said brackets.
 19. The improvement in mechanical integrators as defined in claim 18 in which the pivot point of said lever is offset from a vertical plane passing through the points of contact of said lever with said cage and said track and is disposed in a vertical plane passing through the centers of said balls perpendicular to the axis of said roller. 